Simulation of losses in resonant converter circuits

The mathematical foundation for a generic resonant converter macromodel that is capable of producing transient analyses some three orders of magnitude faster than conventional component-level simulation is described elsewhere by the authors. In this paper, the concept is extended to model and analyse dissipative losses in such a converter. For each of the three main dissipating components (the power diodes, the MOS switches and the inductors), extremely simple phenomenological loss models are developed, which are calibrated by comparison with experimental results. It is then shown, both theoretically and experimentally, that the sensitivity of the overall converter simulation results to the loss model parameters is low, indicating that the models may be used with confidence on other designs under different load conditions. Finally, the simulated and measured responses of a different load configuration (i.e. a practical circuit that was not used to calibrate the loss model) are compared, and it is noted that the results are in excellent agreement. (The simulation results obtained by this technique are also in excellent agreement with the corresponding full component level simulation, but are obtained in around 2.0% of the time.).